/*
  KeePass Password Safe - The Open-Source Password Manager
  Copyright (C) 2003-2017 Dominik Reichl <dominik.reichl@t-online.de>

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 2 of the License, or
  (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
*/

using System;
using System.Collections;
using System.Collections.Generic;
using System.Text;
using System.Diagnostics;

namespace KeePassLib.Keys
{
  public sealed class KeyProviderPool : IEnumerable<KeyProvider>
  {
    private List<KeyProvider> m_vProviders = new List<KeyProvider>();

    public int Count
    {
      get { return m_vProviders.Count; }
    }

    IEnumerator IEnumerable.GetEnumerator()
    {
      return m_vProviders.GetEnumerator();
    }

    public IEnumerator<KeyProvider> GetEnumerator()
    {
      return m_vProviders.GetEnumerator();
    }

    public void Add(KeyProvider prov)
    {
      Debug.Assert(prov != null); if (prov == null) throw new ArgumentNullException("prov");

      m_vProviders.Add(prov);
    }

    public bool Remove(KeyProvider prov)
    {
      Debug.Assert(prov != null); if (prov == null) throw new ArgumentNullException("prov");

      return m_vProviders.Remove(prov);
    }

    public KeyProvider Get(string strProviderName)
    {
      if (strProviderName == null) throw new ArgumentNullException("strProviderName");

      foreach (KeyProvider prov in m_vProviders)
      {
        if (prov.Name == strProviderName) return prov;
      }

      return null;
    }

    public bool IsKeyProvider(string strName)
    {
      Debug.Assert(strName != null); if (strName == null) throw new ArgumentNullException("strName");

      foreach (KeyProvider prov in m_vProviders)
      {
        if (prov.Name == strName) return true;
      }

      return false;
    }

    internal byte[] GetKey(string strProviderName, KeyProviderQueryContext ctx,
        out bool bPerformHash)
    {
      Debug.Assert(strProviderName != null); if (strProviderName == null) throw new ArgumentNullException("strProviderName");

      bPerformHash = true;

      foreach (KeyProvider prov in m_vProviders)
      {
        if (prov.Name == strProviderName)
        {
          bPerformHash = !prov.DirectKey;
          return prov.GetKey(ctx);
        }
      }

      Debug.Assert(false);
      return null;
    }
  }
}
